Router and coordinator have administrative console. This is an app that works by PostgreSQL protocol and you can connect to it by usual psql: 
➜  psql "host=localhost sslmode=verify-full user=demo dbname=demo port=7432"
		SPQR router admin console
	Here you can configure your routing rules
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	You can find documentation here 
https://github.com/pg-sharding/spqr/tree/master/docs

SHOW shards;
 listing data shards 
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 shard id -> shard1
 shard id -> shard2
(2 rows)
Administrative Console is the place where you configure the sharding logic. The router will decide which of the shards to send each request to according to the settings.